The KELLY-SCREAMER is Kelly's own lead-trumpet mouthpiece design. The rim has a remarkably cushioned feel that still provides good slotting and great note accuracy. For comparison, the diameter is near a 13a4a with our KELLY-SCREAMER being a bit shallower. The throat is slightly tighter than a Shew-lead, and the parabolic backbore just under that of a 3E.